


the propensity of lunar soil

by seclusion



Category: Dr. STONE (Anime), Dr. STONE (Manga)
Genre: M/M, author does NOT know what is happening in manga right now, maybe a dash of poetry who knows, therefore author will not tag canon compliance
Language: English
Status: Completed
Published: 2021-02-16
Updated: 2021-02-16
Packaged: 2021-03-17 23:28:34
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 2,903
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29479944
Author URL: https://archiveofourown.org/users/seclusion/pseuds/seclusion
Summary: “You’re rather short,” Tsukasa states, objectively.
Relationships: Ishigami Senkuu/Shishiou Tsukasa
Comments: 12
Kudos: 77





	1. Chapter 1

**Author's Note:**

  * For [chasiu](https://archiveofourown.org/users/chasiu/gifts).



“In several lab tests, a single scoop of replica moon dust proved toxic enough to kill up to 90 percent of the lung and brain cells exposed to it.”

[...]

“Because there's no wind on the moon, the dust never erodes. Instead, grains of moon dust — which are largely the products of micrometeorite impacts — remain sharp and abrasive and can easily slice into an astronaut's lung cells if breathed in too deeply.”

“Moon Dust is Super Toxic to Human Cells” — Brandon Specktor, LIVESCIENCE

With a single glance from him  
and the feeling of sticky-sticky salt air  
on your arm  
your heartbeat in your fingers  
on the Erlenmeyer flask

you are sliced open. It  
is just as well, perhaps  
that the lunar regolith, composed of basaltic and anorthositic rock  
smashed by meteors, crashing hearts  
is something

you understand. Something  
you can counter.

Oh, the water is warm.

He moves like it  
the waves, not the crash but  
the highest arc,  
arcing,  
cresting,  
reaching,  
into the air sky space.

He is all physicality.

Maybe if  
the moon  
the moon, two degrees shy of its zenith  
did not wait so insistently, so persistently, you could, for once, stop  
counting. Stop  
calculating. Just  
watch.

Just  
float, like the electrostatic levitation of moon dust, like the waterless fountains the particles form, spraying deadly blades in their wake,  
to him, to the ocean blue.

And maybe  
he will share your dream and  
teach you how to swim.


	2. Chapter 2

The diameter of Earth is 40,000 kilometers, and without stopping for rest it would take nearly a year to traverse. Including the fact that humans can’t walk on water (yet) or straight through mountains and volcanoes (yet), the journey would likely take around a decade. Without technology, that is. 

Senkuu’s got plans. Tall, huge, break-the-dome-of-the-sky plans. He’s got plans, and science, and therefore technology, so he’s going to circle the world twice over in the time it takes Ginro to make up his mind and re-invent everything once known to man.

To accomplish this, he’ll marry, divorce, date, and break up with anyone. As long as it’s quick and efficient with a clear end in sight, both parties consenting, he’ll do it for science. Even if it’s boring as hell. 

It’s not that Senkuu  _ hates _ romance, per se, but he doesn’t have any interest in it. If he’s going to hit fast-forward on human history, from the Stone Age to the Age of Exploration to the Information Age, he has no time to participate in mating rituals. Taking up brain space worrying about how to make handmade chocolates on Valentine’s or inventing a pen to write love confessions is, to put it in a single word, wasteful. What’s he going to do when a spear flies at him? Think  _ oh, I sure hope they don’t see me get impaled, since that would be really lame and embarrassing? _ No, he’s going to calculate the precise trajectory and velocity to dodge it, or lessen the damage taken at impact. If he’s running physics through his head, there’s no way to entertain romantic notions. 

And besides, he’s  _ pretty sure _ that he’s got someone already, so there’s no need to worry if he’ll be “single and ready to mingle” or just plain “lonely forever”. It’s not, like, ten billion percent sure, and there’s a couple of one millimeter doubts in there, but it’s shown by qualitative  _ and _ quantitative data that Senkuu’s got something. Someone.

He places the test tube back into the rack with tongs and looks up, dusting his hands off on his shirt. Outside the door of their boat laboratory, he can see the edges of Tsukasa’s red cape-thing fluttering; he must be looking at the sea again. 

Senkuu smiles. Even if this one hypothesis can’t be ten billion percent proven without direct trial (and error), he’s content with leaving it as it is. Not aligning with his ultimate scientist image maybe, but it’s a special question. 

  
  


∷

  
  


Apparently, Tsukasa is not looking at the sea. He is, but not in the romantic looking-for-land,  _ how beautifully the water sparkles _ type of way. Just the seafood kind of way. 

“There might be piranhas,” Senkuu warns, joining him on the deck. 

Tsukasa doesn’t take his eyes off the deep blue. He’s so tall that the railing hardly reaches his waist, ending closer to his hips; Senkuu, on the other hand, can rest his elbows comfortably on the wood. “I will be fine.”

“You sure? You’ve still got a bullet wound that hasn’t healed completely yet,” says Senkuu, looking over. Up. Casually, of course. Yeah, he barely comes up to Tsukasa’s (huge, primate) shoulder, and if he were to accidentally stumble to the left his head would hit solid muscle, which is basically solid rock, and Senkuu understands the dangers of head injuries after having watched Byakuya undergo astronaut training, so he would like to avoid a concussion and possible amnesia. It really would be disastrous for the human race if he were to forget all his scientific knowledge. 

Tsukasa catches his gaze, fast, before he can unglue it from the rock-shoulder; thankfully, Tsukasa’s mind is just as romance-free as Senkuu, and he will understand that Senkuu was merely making an observation and determining a risk factor. His eyes are the same colour as his hair, Senkuu notices, objectively, but instead of the glossy tint there’s a hint of amber mixed in. A scientist’s attention to detail is a handy skill to have.

The sudden, upward tilt to his lips knocks something loose inside of Senkuu, and a quippy remark fails to rise to his lips when Tsukasa strips off his tattered yukata and drapes it over the railing. Senkuu doesn’t remember muscles being quite that defined when he studied anatomy, but it looks like the impulse directed to his head from a possible collision with the wall that is Tsukasa could result in death. Again, physics — how would the momentum from his collision be absorbed by Tsukasa? He probably wouldn’t budge an inch, or even notice. Fascinating. 

“I will be fine,” he says again, and Senkuu figures it’s true. Tsukasa doesn’t lie. He hitches one extremely bare leg up and pushes off over the side of the ship, diving into saltwater in a perfect arc. There’s the smallest of splashes as he enters the water, ripples spreading outwards.

Absentmindedly, Senkuu runs a hand over the surprisingly soft material of Tsukasa’s clothes. It’s crudely made, edges jagged and nothing like the lion’s pelt — the very one that led to their dramatic first meeting. He’s kind of glad the lion attacked them that day; impending death aside, it’s likely that Tsukasa wouldn’t have been revived. He can overlook the attempted murder and establishment of an anti-technology anti-science empire now that Tsukasa’s become a valuable ally. Yes, ally with amber-brown eyes and a Michelangelo sculpture-esque body, literally. 

Senkuu’s interrupted from his thoughts as Ginro stumbles over and vomits over the side, hurling up whatever he ate for breakfast and lunch. Kinro rubs his back sympathetically, sending Senkuu a worried glance. 

“I made medicine for seasickness, didn’t I?” Senkuu asks, covertly shifting Tsukasa’s clothes away from Ginro. It wouldn’t do to have any of the puke-chunks spray onto it, since Tsukasa doesn’t have a change of clothes and making him walk around naked would be rather cruel. In fact, Senkuu muses, Tsukasa’s pale skin makes him more sensitive to the blazing, equatorial sunlight. It’d be good to develop a sunscreen for him. And the rest of the crew. 

“I think it was the oysters,” Ginro moans, then heaves again. 

  
  


∷

  
  


When Tsukasa comes back up, hair drenched and no longer wavy from the sheer amount of water that’s saturated it, Senkuu throws a net over the side so he can catch fish. He snatches it out of the air with one long arm, somehow avoiding entanglement easily. Senkuu thinks it’d be hilarious if he got wrapped up though, excepting the risk of drowning — he’d be like the Anderson fairy tale, The Little Mermaid. Actually, Tsukasa looks like a mermaid — merman himself, fanned-out hair and lithe, graceful limbs. 

“The piranhas got you yet?” he calls over, raising his voice over the salt breeze. 

“I got a few of them,” Tsukasa yells back. He holds up two wiggling triangles in one hand, which Senkuu takes to be piranhas. 

He looks as much at home in the water as he is on land. Senkuu wouldn’t be surprised if he could swim faster than a shark, actually, or beat a shark. Come to think of it, didn’t he catch one just the other day? Senkuu has no idea where one obtains the physical prowess necessary to fight a shark into submission, but it’s intriguing that humans have such an ability. 

“Don’t catch any oysters, okay? And get back on the ship on the other side, Ginro vomited over here earlier.”

Tsukasa makes a signal of assent and disappears again with barely a wink, like a diamond earring lost to the seas. Senkuu turns back to give Ginro water, unworried; he knows Tsukasa will come back anyway. Always.

  
  


∷

  
  


As Senkuu pulls a devastatingly naked Tsukasa back onto the ship, he vows to crack the long-pursued mystery of love with careful experimentation. He’s known this for a long time, what the thundering of his heart and the knee-weakening joy really meant — he just didn’t expect the symptoms to be this intense. There’s really no investigated scientific reason for the way Senkuu wants to lick the water pooled in his collarbones. He already knows it’s three-point-five percent salt, after all. 

The sunlight causes every bead of water slowly sliding down Tsukasa’s chest to glint, and for the first time Senkuu thinks something is truly unfair. All of his bad luck, escaped by science, is catching up to him. A stray droplet glides into the dip between his abs, and — Senkuu shoves Tsukasa’s sun-baked clothes back at him, muttering something about going back to the lab.

Return the world to its former glory, reach the moon, and  _ then _ he can kiss Shishiou Tsukasa, Senkuu tells himself. 

  
  


∷

  
  


“You’re rather short,” Tsukasa states, objectively. He looms over Senkuu, nearly blocking out the lights. They’ve started moving again, white sails billowing outwards, the ship settling into its familiar rocking. Ginro is once more clutching onto the deck railing, having mistook the undistilled saltwater for drinking water. Kohaku, sipping her Piquant Cinderella, unsympathetically watches him struggle.

“No kidding,” Senkuu deadpans, discarding the fish bones. Pushing up to his feet, he finds himself staring straight at Tsukasa’s chest. Objectively, the curve of his pectorals are a sign of physical health. Subjectively, it looks great. “And you’re a two meter giant, if you haven’t noticed.”

Dipping his head to check out his own body, Tsukasa frowns. “I’m one meter and ninety-five centimeters, not two meters.”

“Estimations are occasionally necessary for efficient execution,” Senkuu snaps back, trying not to notice the lone strand of hair that’s fallen forward, brushing his own shoulder. He fails, noting that the threads are drier and rougher than normal, probably due to the salt from the ocean leaching out moisture. 

He latches onto this opportunity, since it’s what all scientists do, and herds Tsukasa into the lab. Instead of forcing him to sit down on the small wooden stool that he usually makes Taiju sit on so as to not destroy anything, he lets Tsukasa lean over his shoulder as he mixes up shampoo and conditioner. He smells like the sea, stronger than the ocean air Senkuu now breathes daily. 

Tsukasa is a good person to have in the lab. There’s no threat of equipment abuse, and his questions are interesting rather than moronic; he might not provide regular breakthroughs like Chrome does, or work on the same plane of existence as Dr. Xeno, but his presence is quiet and attentive. Senkuu allows him to flip switches and hand him ingredients, explaining the process as he goes. 

“A little less salt and lemon, respectively, should do the trick,” he finishes, holding up the glass beaker. The viscous, goopy liquid sludges around triumphantly in the artificial yellow light. 

Dragging the wooden stool up to the deck, Senkuu forces Tsukasa into the seat and shoves the beakers unceremoniously into his hands. He almost trips as he lugs a large bucket of distilled water over, mind snagging on the sight of Tsukasa’s knuckles; they’re swollen from his years of fighting. Righting himself, he promptly stumbles again as Tsukasa looks up at him.

Ah, love is life-threatening, as zero science textbooks have ever said. 

Twirling Yuzuriha’s comb in one hand, Senkuu fluffs out the waterfall of hair in front of him. This position allows him to observe from above. He gloats, “Who’s the taller one now?”

“I’m twenty-four centimeters taller than you,” says Tsukasa, like Senkuu doesn’t know that. 

“Yes,” Senkuu responds dryly. “I’m aware. I could probably use you as a mode of transportation, since your top speed likely far outstrips that of our mobile lab, but considering how nausea-inducing it would be it wouldn’t be my first pick.”

Tsukasa laughs, and Senkuu jumps — it’s an infrequent sound, but it’s warm and cloaks his ears wonderfully. He’d like to hear it again, he thinks a little wistfully as he works his way through sand-clumped tangles. Small grains fall out onto the wood, showering down and joining the sand already collected in the thin cracks. 

Water drips onto the fallen sand as Senkuu soaks Tsukasa’s hair completely, wiggling his fingers so Tsukasa can hand him the shampoo. It works like a charm; any remaining tangles that the comb couldn’t conquer yields to the coconut oil, allowing Senkuu to rake his fingers through with ease. 

“I added a bit more oil to this one than the one for Kohaku,” Senkuu explains, lathering the liquid into bubbles. When he parts the now-silky hair down the middle, he finds that the nape of Tsukasa’s neck is the palest part of him; always protected from the sun. “Wait a minute — you weren’t around for the Kohaku beautification episode, right?”

“I was dead, yes.” Tsukasa tilts his head up, clever, amused amber catching the light. 

Without a second thought, Senkuu presses his lips to the smooth skin of his forehead, right where a crack should be; instead, he gets war paint smeared on his lips. Tsukasa smirks at him as he wipes it off with a grimace, confirming his hypothesis. No more one millimeter doubts. 

Senkuu’s still holding out, though! He’s doing everything in order like he planned to. Forehead kisses don’t count, he insists to himself. It’s not even first base. He rinses the last of the shampoo out, water dribbling steadily onto the deck.

“I’ve never thought about going sailing,” Tsukasa admits suddenly. There’s an awe in his voice that tugs at Senkuu, and he brushes back a strand of dark hair gently. “I was always fighting. And counting money, and worrying about my sister’s condition. Most of my free time was spent training, but now I have time to think and build. It turns out the world is a lot larger than I expected, and a lot smaller, because I can actually go places. See everything for myself.

“It’s nicer here than I imagined. Thank you for taking me to sea, Senkuu.”

Rather than getting weepy, Senkuu places both hands on either side of Tsukasa’s head and angles it upwards, towards the night sky. Towards the shining, waxing moon. “I’m taking you there next.”

They watch as the stars begin to appear, tiny white pinpricks of light belying their true monumental nature. To the moon, and beyond; it’s the universe, too wide to fathom. Ninety-three billion light years in diameter. Senkuu can dream, though.

“You ought to kiss me,” declares Tsukasa, with no delicacy whatsoever. He says it like himself: straightforward, clear, unambiguous. Everything Senkuu prizes in the scientific process. 

“Now, what scientific benefits would that give me? I’m not about to perform a transferral of saliva if there’s no result to be had,” Senkuu teases, heart probably-definitely-not skipping. 

Flesh isn’t glass, and yet Tsukasa looks right through him. “You want to, though.” 

It could be called cockiness, but it’s more of the truth. Both of them understand — whatever’s fizzing like soda pop between them isn’t going to stop anytime soon, and neither of them want it to. 

And so Tsukasa’s not wrong, but Senkuu’s hardly going to back down from him and the plan. “I’ll kiss you on the moon, Tsukasa. How’s that?”

“But the dust on the moon is potentially deadly if breathed in, so it’s safer here on Earth,” Tsukasa points out, but he says it in such a way that Senkuu can tell he’s playing along. Says it in such a way that Senkuu can tell he’ll wait for as long as he needs to, always, forever.

“On the moon,” he repeats, and it’s a promise that’ll come true.

  
  


∷

  
  


The diameter of the moon is 3,500 kilometers, and the distance to Earth is 385,000 kilometers. Humans do not produce oxygen on their own (yet), and neither can they walk on air and in space (yet), so travelling from Earth to the moon is impossible. Without technology, that is. 

Senkuu’s got plans. Gargantuan, colossal, eat-a-black-hole-massive plans. He’s got plans, and science, and therefore technology, so he’ll travel to the moon, annihilate the dangers of moon dust, and kiss a boy with amber eyes. 

  
  


**Author's Note:**

> Here is the [ moon dust article.](https://www.livescience.com/62590-moon-dust-bad-lungs-brain.html#:~:text=Moon%20dust%20clings%20to%20clothing,astronauts%2C%20a%20new%20study%20finds.&text=In%20space%2C%20they%20say%2C%20no,visited%20the%20moon%20in%201972.)


End file.
